Are Animmontages time stamped and how do they work.

I have been using AnimMontages to play animations for my character until now.

Recently I am changing approach to play the animations to something like this

I will use replicated variables to play the animations on other clients. I wanted to know if using this would be better compared to AnimMontages since I have heard AnimMontages are time stamped.(I still used replicated uint8 s to play animmontages on other clients)